1. Field of the Invention
The present invention relates to a display device that includes inspection wiring lines for inspecting a wiring defect, an inspection method for inspecting a wiring defect on the basis of inspection signals that are input to the inspection wiring lines of the display device, and an inspection device that generates inspection signals, which are input to the inspection wiring lines of the display device.
2. Description of the Related Art
A display device, such as a liquid crystal display device, includes an effective display section that is composed of display pixels arranged in a matrix. The effective display device includes a plurality of scan lines extending along rows of the display pixels, a plurality of signal lines extending along columns of the display pixels, switching elements that are disposed near intersections between the scan lines and signal lines, and pixel electrodes that are connected to the switching elements.
A wiring line group that connects a scan line driving circuit and the scan lines is, in usual cases, disposed on one end side of the effective display section. By inputting inspection signals to odd-number-th scan lines and even-number-th scan lines, it is possible to inspect a wiring defect on a panel, such as short-circuit or line breakage in the effective display section.
On the other hand, there has been proposed such a layout that an odd-number-th wiring line group comprising lines connected to odd-number-th scan lines is disposed on one end side of the effective display section, and an even-number-th wiring line group comprising lines connected to even-number-th scan lines is disposed on the other end side of the effective display section (see, e.g. Jpn. Pat. Appln. KOKAI Publication No. 06-160898 and Jpn. Pat. Appln. KOKAI Publication No. 2001-013892). This layout is optimal for a structure that adopts a single driving IC chip in which a scan line driving section and a signal line driving section are integrated.
In the case of this layout, by inputting inspection signals to the odd-number-th scan lines and even-number-th scan lines, it is possible to inspect a wiring defect in the effective display section. However, it is not possible to inspect a wiring defect in each of the wiring line groups. Consequently, a panel with a wiring defect in the wiring line group, which could not be detected, may go out to a subsequent fabrication step. In the subsequent fabrication step, expensive components, as a driving IC chip and a flexible print circuit board (FPC), are mounted. Thus, if the defective panel goes to the subsequent fabrication step, this leads to a decrease in manufacturing yield.